He went to primary school in Burracoppin and high school in nearby Merredin, graduating in 1989[4] Ian then worked on the family farm and played for Burracoppin Cats in the Eastern Districts Football League until 1993 when he went to play for West Perth Football Club.
1996 was a successful season for Downsborough, he played as an undersized ruckman replacing Ryan Turnbull.
He played 19 games including the Eagles qualifying final vs Carlton but he was dropped for the semi-final.
West Coast also traded Shane Bond and Brayden Lyle to the Power to ensure the Eagles could get the #1 pick in the 1996 AFL draft as compensation for losing Downsborough.
Downsborough remained a backup option for the Crows in 1998 missing out on playing in their Grand Final win.